State Space Initiation for Blind Mobile Terminal Position Tracking

Blind localization and tracking of mobile terminals in urban scenarios is an important requirement for offering new locationbased services, handling emergency cases of nonsubscribed users, public safety, countering IEDs, and so forth. In this context, we propose a track-before-detect scheme taking explicitly advantage of multipath propagation in an urban terrain by using a priori information about the known locations of the main scattering objects such as buildings. This information is made available for localization and tracking by a real-time ray tracing technique based on a 2D geographic database. This allows the prediction of the directional and temporal structure of the received multipath components for an arbitrary transmitter position. We consider a single observing station where the direction and the relative time of arrival of the received multipath components can be estimated by an antenna array. By a likelihood function, which is algorithmically defined for a randomly distributed set of potential transmitter positions, these measurements are compared with those being expected by ray tracing. This likelihood function is the key component of a track-before-detect scheme providing initial state estimates for mobile transmitter tracking using a particle filtering technique.